1. Field
The present disclosure relates to a lawn mower robot having a wheel driven using an electric motor as a power source.
2. Background
A lawn mower is a device for trimming grass planted on the yard or playground at home. Such lawn mowers may be divided into household mowers for household use and tractor mowers for use on a large playground or farm.
For household lawn mowers, there exist walk-behind type mowers in which a person mows grass while directly pulling a lawn mower from behind and hand type lawn mowers in which a person carries a lawn mower by hand.
However, both types of lawn mowers require a user to directly operate the lawn mowers.
Especially, in a busy daily life, it is difficult for the user to directly operate the lawn mower to cut the lawn of the yard, and therefore, workers are mostly hired outside, resulting in employment costs.
Accordingly, automatic robot-type lawn mowers for preventing the occurrence of such additional costs and reducing the user's labor have been developed. Such an automatic robot-type lawn mower is provided with four moving wheels at a lower portion of the vehicle body.
For example, of the four moving wheels, front wheels are capable of turning direction, and rear wheels are provided with wheels that rotate using a driving force of a motor.
However, when some of moving wheels in the related art are caught on a cliff and floating in the air from the ground without touching the ground, a safety accident may occur because sensors capable of sensing it is not provided therein.
In addition, a gear box is provided between a conventional wheel and a motor, and gears are coupled to each other in the gear box so that a rotational speed of the motor is reduced by a gear ratio and transmitted to the wheel.
For the gears provided in the conventional gear box, a metal gear or a low-cost plastic gear may be integrated thereinto depending on the type of the gear.
However, according to a lawn mower robot in the related art, a fastening structure between a body and a gear box of the lawn mower robot may be different depending on which type of gear between the metal gear and the plastic gear is applied thereto, thereby causing difficulty in replacing the gear box having a different type of gear on the same lawn mower robot.